Polymerization of olefins to oily polymers



Patented June 11 1946' UNITED STATES PATENT oFFics POLYMEBIZATION F.OLEFINS TO" (3H4? POLYMERS Arthur B. Hersberger, Drexel Hill, Pa.,assignor 4 to The Atlantic Refining Company, Philadelphia, Pa., acorporation of Pennsylvania No Drawing. Application November 25, 1943,Serial No. 511,748

oleflns, which term I shall use herein and in the appended claims todesignate olefins of from two to, nine carbon atoms, are characterizedby low yields, particularly when operated on a commercial scale.According to the present invention, in-excess of 80 per cent by weightof the olefin or oleflns treated may be converted to oil of lubricatingoil viscosity and with no substantial increase in cost.

My process is executed by contacting an olefin liquid comprising anolefin of not more than three carbon atoms, which olefin is mostpreferably propylene because of the difllculties incident to theliquefaction. of ethylene, at a temperature of from -10 C. to 35 C. withan active Friedel- Crafts halide catalyst in the presence of a. solventfor the catalyst which is substantially inert under the reactionconditions.

Although I prefer anhydrous aluminum chloride as theactive-Friedel-Crafts halide catalyst,

I may use in lieu thereof, for example, aluminum bromide, aluminumiodide, tin tetrachloride, titanium tetrachloride, ferric chloride,ferric bromide, or the like. Solvents, in the presence of which thereaction is carried out, are distinguished from other organic solvents,in which the metal halide catalysts employable herein are also solublein that they do not form inactive complexes with such catalysts, or inany other way act to hinder the progress of the polymerization. Thesolvent employed is most suitably is not limited to mixtures containingonly two jected to treatment comprises propylene and isobutylene.Usually I employ a mixture containing from 20 to per cent by weight ofpropylene since I have found that the presence in the mixture of eithera larger or smaller amount of propylene has an adverse efiect on theviscosity index of the resulting oil. The treatment of a mixture ofpropylene and isobutylene containing in excess of 70 per cent propylene,however,-

may be carried out to give a high yield of a high viscosity oil welladapted for use in certain applications, such as in the lubrication ofsteam cylinders, where high viscosity is essential and the viscosityindex of the oil of relatively minor importance. If desired, such oilsmay be used in the form of blends with Pennsylvania lubricating oils orwith synthetic oils having temperature-viscosity characteristicscomparable to Pennsylvania lubricating oils.

I have produced oils of highest viscosity by treating propylene in theabsence of any other olefin, but I may prepare oils from mixtures ofpropylene and normal butylene which are nearly as viscous and which,atthe same time, show a higher viscosity index. The copolymerizationwith propylene of olefins of from five to nine carbon atoms, forexample, octylenes, such as di-isobutylene, or straight or branchedchain amylenes,

hexenes, or heptenes, may be carried out according to the hereindescribed method to yield oils, which, insofar as viscosity index is,concerned, are fully the equal of high grade Pennsylvania lubricatingoil. Because of the relatively low viscosity of such oils, they mayperhaps be most advantageously employed in blends .with oils-of highviscosity, for example, an oil prepared according to the invention bypolymerizing propylene alone. The following inspection is typical of anoil produced from a mixture containing 72 parts by weight ofdi-lsobutylone and 28 parts by weight of propylene:

Gravity (A. P. I.) 42.8' Saybolt viscosity at F.. 51.7" Sayboltviscosity at 210 F 34.0" Viscosity index L 100 My invention as appliedto mixtures of oleflns olefins or-to mixtures which are free ofnon-polymerizable constituents, e. g., saturated hydrocarbons; thus, Imay treat all or a part of a cracked distillate, which may have beenproduced, for example, by the cracking of a gas oil or wax fraction. Itis essential for operation according to the invention that thedistillate treated contain an olefin of not more than three carbonatoms, preferably propylene.

The following is illustrative of the detailed practice of my invention:A mixture of propylene and isobutylene containing from 25 to 75 per centof propylene, preferably 40 to 60 per cent, is liquefied and isthereafter diluted with from to 2 volumes of ethyl chloride. The dilutedsolution is then contacted with a suitable polymerization catalyst. Forexample, the diluted solution is placed in a suitable pressure vesselsuch as an autoclave, and is then sprayed with a 1 per cent solution ofanhydrous aluminum chlo- 'ride in ethyl chloride by means of anatomizing used in the case of mixtures consisting of propylene andisobutylene.

Olefins treated according to the hereindescrlbed process may be derivedfrom petroleum sources or may be prepared, for example, by the catalyticor non-catalytic dehalogenation of alkyl halides,

by the removalof waterfront alcohols, or by the' polymerization ofsimpler olefin compounds, e. g., di-isobutylene from isobutylene.

In the accompanying table, the characteris from a mixture of propyleneand normal butene.

Table I Reaetants, percent ggl Yield, GravitIy Viscosity percent (A. P.index Propylene Isobutylene 100 F. 210 F.

100 75-80 2-35. 2 2430-3450 108-128 so so so 34.9 12s? 82. o 5010 50 5085 35. 7 539 63. 2 85. 42.8 51 mol) 57.2 (1 mol) 70 34.4 1374 100 87 42.8 1 mol) 57. 2 (1 11101) 68 84. 5 1259 91. 8 80 75 85 34. 6 547 63. 5,86

\ Butane-1 42. 8 (l moi) 67. 2 (1 mol) 64 V 35.0 2370 117 61 1 Distilledfraction.

effect the desired reaction. .During the reaction,

which is conducted under a pressure sufficient to maintain the olefinsin the liquid state, the reaction temperature is' controlled through theuse of suitable refrigerants such as ice and water, brine, etc. Thereactants are vigorously agitated throughout the reaction, completion ofwhich is marked by the cessation of the evolution of heat. The reactionis of extremely short duration Recovery of the product polymer iseffected by washing the reacted mixture with water to remove thecatalyst as the metal hydroxide, and distilling ofi the unreactedolefins. water wash, the reacted mixture .may be diluted as with a lightnaphtha fraction to reduce the viscosity of the polymer.

Applying the catalyst solution in the form of finely divided liquidparticles is highly advan-' tageous from the standpoint of preventinglocal overheating at the point of first contact of the i From the tableit will be noted that the oils produced using equi-molecular proportionsof propylene and isobutylene are possessed of the best all-roundcharacteristics. In order to test the resistance of these oils towardoxidation, samples thereof, together with a sample of the-oil producedfrom propylene alone, were subjected to an oxidation test whichcomprised heating the Prior to the olefin liquid with the catalystsolution. However,

I may operate by introducing a relatively coarse stream of the catalystsolution into contact with the olefin liquid, such stream being fed tothe reactor, of course, under a pressure sufilcient to overcome thevapor pressure of the reactants. Dilution of the olefin liquid prior tocontacting it with the catalyst solution is not essential, but betterresultsare usually obtained. It is important that the temperature'beheld within the limits specified, i. e., -l0 C. to 35 C. andparticularly that lower temperatures be avoided. I have'found that attemperatures of the order of, for example, 50 C. to --100 C., little ifany polymerization of the propylene-containing mixtures will occur, andeven at --20 C. poor yields are generally obtained; When the olefinliquid samples at 340 F. for 96 hours, while blowing them with airintroduced at a rate of 3 liters per 100 cc. of oil per hour. In eachinstance less than 8 milligrams of sludge developed in the oil for-each10 grams of oil subjected to'the test. An S. A. E. 30 solvent refinedoil when subjected to the same test showed 95 milligrams of sludge per10 grams of oil tested.

I claim:

l. The,method of producing lubricating oil, which comprises providing amixture of liquid propylene and liquid isobutylene, the propylenerepresenting 40% to of the mixture, bringing the temperature of themixture within the range of l0 C. to +35 C., and spraying the mixturewith a solution of a Friedel-Crafts type catalyst in a lower alkylhalide, said catalyst solution being applied in the form of finelydivided liquid particles at a temperature between 10 C.

Bil

comprises an olefin of more than four carbon atoms, it is advisable toemploy a 3 to 5 per cent catalyst solution instead of the 1 per centsolution 78 and +35 C. and the mixture being vigorously agitated duringthe addition of the catalyst solution and the ensuing polymerizationreaction.

-2. The method of producing lubricating oil, which comprises providing-a. mixture of liquid propylene and liquid isobutylene, the propylenerepresenting 40% to 60% of the mixture, diluting the mixture with alower alkyl halide, bringing the temperature of the diluted mixturewithin the range of 10 C. to +35 C., spraying the diluted mixture with asolution of a Friedel-Crafts type catalyst in a lower alkyl halide, saidcatalyst solution being applied in the form of finely divided liquidparticles at a temperature between -l0. C. and +35 C. and the dilutedmixture being vigorously agitated during the addition of diluted mixturewith asolution of aluminum chloride in ethyl chloride, said aluminumchloride solution being applied in the form of finely divided liquidparticles at a temperature between 10 C. and +35'C. and the dilutedmixture being vigorously agitated during the addition of the aluminumchloride solution and the ensuing polymerization reaction.

4. The method. of producing lubricatingoil, which comprises providing amixture of liquid propylene and liquid isobutylene, the propylenerepresenting 40% to 60% of the mixture, diluting the mixture with from0.5 to 2 volumes of ethyl chloride, bringing the temperature of thediluted mixture within the range oi 10 C. to +35 C.

. 6 v and spraying the diluted mixture with a' solution of aluminumchloride in ethyl chloride, said aluminum chloride solution beingapplied in the form or finely divided liquid particles at a temperaturebetween 10 C. and +35 C. and thedlluted mixture being vigorouslyagitated during the addition of the aluminum-chloride solution and theensuing polymerization reaction 5. The method of producing lubricatingoil, which comprises providing a mixture of liquid propylene and liquidisobutylene in equi-molar proportions, diluting the mixture with 0.5 to2 volumes of ethyl, chloride, bringing the temperature of the dilutmmixture within the range of 10 C. to +32? 0., and spraying the dilutedmixture with a solution of aluminum chloride in ethyl chloride, saidaluminum chloride solution being applied in the form of finely dividedliquid particles ata temperature between 10 C. and +35 C. and thediluted mixture being vigorously agitated during the addition of thealuminum chloride solution and" the ensuing polymerization reaction.

' ARTHUR B. HEBSBERGER.

